Advances in the study of neurology and clinical psychology have led to advances in the methods and tools used to assess and analyse emotional responses of individuals to various sensory stimuli. According to Ann Marie Barry, in her book ‘Visual Intelligence: Perception, Image, and Manipulation in Visual Communication’ (State University of New York: 1997), up until the mid-1980s it was widely believed that sensory information was first processed via conscious and unconscious thought, prior to the generation of an emotional response, for example via the autonomic nervous systems and the endocrine system. The most extreme proponents of this view argued that cognitive appraisal was a necessary precondition for emotional reaction.
However, from about the mid-1980s the neurobiologist Joseph LeDoux, and others, conducted various experiments mapping the operations of the so-called ‘limbic system’ in greater detail. This research indicated that, although emotional functions might be mediated by other brain regions, the amygdala (a subcortical region buried deep within the temporal lobe) strongly determines our emotional response to sensory stimuli. In Barry's words, the amygdala acts ‘as a sentry to ready the body in response to danger’ and ‘attaches emotional significance to incoming data and readies the body to act in intense situations by signalling the hypothalamus to secrete hormones, initiating a fight-or-flight response. It alerts the autonomic nervous system and prepares the muscles for movement; and it warns the brainstem to secrete chemicals that heighten alertness and reactivity in key areas of the brain. All of this can occur independently of a conscious decision to act.’
As a consequence of the work of LeDoux, and many others since, the broad consensus is now that much of cognition is no more than a post-response rationalisation for the emotions resulting from the effect of sensory stimuli on the limbic system. LeDoux has hypothesised that this may explain our general inability to fully understand the origins and operations of our emotions, since the cortical systems responsible for understanding only become involved after the fact.
One outcome of this neurological research is an appreciation that human beings' emotional responses to sensory stimuli cannot be effectively measured through mechanisms, such as questionnaires, which necessarily require high-level cognitive processing. Accordingly, neuroscientific research has resulted in the development of various techniques to measure unconscious emotional responses. This is possible because, as the foregoing discussion indicates, emotions necessarily involve a physiological component, which is susceptible to measurement. Various physiological variables have been used to measure changes in emotions, including galvanic skin response (GSR), blood pressure, heart rate and respiration. It is no coincidence that such readily measured variables are also commonly used by so-called ‘lie detector’, or polygraph, apparatus, the basis of which is identification of telltale emotional responses to the expression of untruths. More-sophisticated measurement techniques include electromyography (EMG), electrocardiography (ECG), electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). All of these physiological techniques have in common an ability to identify the presence of an emotional response, often in real-time, but little or no capacity to differentiate between different types of emotional response. An unidentified emotional response is nothing more than arousal (e.g. of the limbic system), from which little might be concluded, particularly since there may be no differentiation between quite distinct emotions (e.g. love and hate).
In the field of cognitive linguistics it has been noted that metaphors appear able to evoke an emotional response directly, without cognitive processing. (Slingerland, E. D., ‘Conceptual Blending, Somatic Marking and Normativity,’ Cognitive Linguistics, Volume 16 No. 3, 2005, pages 557 to 564; Kovecses, Z., ‘Metaphor and Emotion—Language, Culture, and Body in Human Feeling,’ Cambridge University Press, UK: 2000.) The process of acquiring and exercising such metaphorical connections is called ‘conflation’, whereby individuals acquire some common metaphors automatically and unconsciously via the process of neural learning, and through experience.
As a result of these discoveries and observations, it has been proposed that animated visual metaphors, rather than verbal questioning, may provide a more-effective mechanism to measure emotional response. An early attempt to harness this idea is the Metaphorix™ system, developed by Conquest Research and Consultancy Ltd (www.metaphorixuk.com). Trials of this system have demonstrated a loose correlation (Pearson Correlation Coefficient of 0.78) between emotional response as measured via Metaphorix scales, and success in the marketplace of products associated with corresponding brands. (Penn, D, ‘Metaphors Matter,’ ARF Conference, New York, April 2008.) However, these trials demonstrated only that a higher level of consumer engagement with a brand (measured as emotional response to the brand) is correlated with a higher market share. This result seems unsurprising, and furthermore provides no information as to cause and effect, nor is it able to explain the many outliers that defy the general trend.
It is therefore apparent that a need remains to provide improved methods for measuring emotional response of individuals to sensory stimuli. While such methods may find application within the field of market research (i.e. as with the Metaphorix™ system), effective tests for emotional response may have many other applications, for example in the fields of clinical psychology and neurology.